Add zStandard support

Enable zstd support By -DWANT_ZSTD=On (Off by default).
Uses the exported targets produced by the cmake build script of zstd.
Use ZSTD_PREFER_STATIC=Off to link with the shared lib version of zstd.

CMakeLists.txt

@@ -10,7 +10,9 @@ set(API_VERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}")
 set(BUILD_VERSION "${PROJECT_VERSION}")
 
 option(WANT_ZLIB "use zlib (ability to decompress layers data) ?" On)
+option(WANT_ZSTD "use zstd (ability to decompress layers data) ?" Off)
 option(BUILD_SHARED_LIBS "Build shared libraries (dll / so)" Off)
+option(ZSTD_PREFER_STATIC "use the static build of zstd ?" On)
 
 set(EMSCRIPTEN False)
 if(CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
@@ -48,6 +50,18 @@ else()
     message("Zlib not wanted")
 endif()
 
+if(WANT_ZSTD)
+    target_compile_definitions(tmx PRIVATE WANT_ZSTD)
+    find_package(zstd REQUIRED)
+    if (ZSTD_PREFER_STATIC)
+        target_link_libraries(tmx zstd::libzstd_static)
+    else()
+        target_link_libraries(tmx zstd::libzstd_shared)
+    endif()
+else()
+    message("zstd not wanted")
+endif()
+
 include(FindLibXml2)
 find_package(LibXml2 REQUIRED)
 target_link_libraries(tmx LibXml2::LibXml2)

examples/data/b64zstd.tmx

@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<map version="1.2" tiledversion="1.3.5" orientation="orthogonal" renderorder="right-down" width="28" height="18" tilewidth="32" tileheight="32" infinite="0" backgroundcolor="#ffff7f" nextlayerid="5" nextobjectid="5">
+ <properties>
+  <property name="alt" type="file" value="csv.tmx"/>
+  <property name="bool_false" type="bool" value="false"/>
+  <property name="bool_true" type="bool" value="true"/>
+  <property name="colour" type="color" value="#cc1a1a1a"/>
+  <property name="multilines">foo
+bar
+baz</property>
+  <property name="pi" type="float" value="3.14"/>
+  <property name="xml" value="libxml2"/>
+ </properties>
+ <tileset firstgid="1" name="base" tilewidth="32" tileheight="32" spacing="1" tilecount="9" columns="3">
+  <image source="numbers.png" width="100" height="100"/>
+  <tile id="0">
+   <properties>
+    <property name="number" type="int" value="1"/>
+   </properties>
+   <objectgroup draworder="index">
+    <object id="0" x="11.75" y="4.75" width="10.25" height="25.25"/>
+   </objectgroup>
+  </tile>
+  <tile id="1">
+   <properties>
+    <property name="number" type="int" value="2"/>
+   </properties>
+  </tile>
+  <tile id="2">
+   <properties>
+    <property name="number" type="int" value="3"/>
+   </properties>
+  </tile>
+  <tile id="4" type="five"/>
+  <tile id="6">
+   <animation>
+    <frame tileid="0" duration="200"/>
+    <frame tileid="1" duration="300"/>
+    <frame tileid="2" duration="400"/>
+    <frame tileid="3" duration="500"/>
+    <frame tileid="4" duration="600"/>
+    <frame tileid="5" duration="700"/>
+    <frame tileid="6" duration="2000"/>
+   </animation>
+  </tile>
+ </tileset>
+ <group id="1" name="Group">
+  <imagelayer id="2" name="Image">
+   <image source="bg.jpg" width="896" height="576"/>
+   <properties>
+    <property name="alt" value="rainbow"/>
+   </properties>
+  </imagelayer>
+  <layer id="3" name="Layer" width="28" height="18">
+   <data encoding="base64" compression="zstd">
+   KLUv/WDgBt0FAHQCBQAAAAMFBgMBAwQDCAYDAQQGCQMCCQcDCQUGCQcIAgUDAwQFAAAAYKBgPQEAgwpmDgI4Afyc+zIh+QH/mAjS3eL3YCA++G4W88cZ7WXdp3Q+buteXb5C+/Bb19DMQ3iBGb1CHFyS3Bn4APOSLyLFnjOyM2LFHxYYPBiciXaDO4yw8f6IIfC8nRWgF/LEHAzOuBr6uIszJIFNgvSemyl6SmpbfgLe7qwNjH+USwh7g6Vl+vJaq0vg9Pw=
+  </data>
+  </layer>
+ </group>
+ <objectgroup color="#aa0000" id="4" name="Objects">
+  <object id="1" name="square" type="spawn" x="128" y="128" width="192" height="192" rotation="22.5"/>
+  <object id="2" name="polygon" x="492" y="325">
+   <polygon points="20,-5 -44,-197 180,-229"/>
+  </object>
+  <object id="3" name="polyline" x="174" y="477">
+   <polyline points="-14,3 50,-61 114,3 178,-61 242,3 306,-61 370,3"/>
+  </object>
+  <object id="4" name="ellipse" x="672" y="352" width="160" height="160">
+   <ellipse/>
+  </object>
+  <object id="5" name="text" x="4" y="0" width="110" height="20" rotation="10">
+   <text wrap="1" color="#ff0000" bold="1" italic="1">Hello World</text>
+  </object>
+ </objectgroup>
+</map>

src/tmx.h

@@ -405,6 +405,7 @@ typedef enum _tmx_error_codes {
 	E_BDATA  = 20,    /* B64 bad data */
 	E_ZDATA  = 21,    /* Zlib corrupted data */
 	E_XDATA  = 22,    /* XML corrupted data */
+	E_ZSDATA = 23,    /* Zstd corrupted data */
 	E_CDATA  = 24,    /* CSV corrupted data */
 	E_MISSEL = 30     /* Missing element, incomplete source */
 } tmx_error_codes;

src/tmx_utils.c

@@ -212,6 +212,51 @@ char* zlib_decompress(const char *source, unsigned int slength, unsigned int rle
 
 #endif /* WANT_ZLIB */
 
+#ifdef WANT_ZSTD
+
+#include <zstd.h>
+
+char* zstd_decompress(const char *source, unsigned int slength, unsigned int rlength) {
+	char *res;
+	size_t ret;
+
+	if (!source) {
+		tmx_err(E_INVAL, "zstd_decompress: invalid argument: source is NULL");
+		return NULL;
+	}
+
+	res = (char*) tmx_alloc_func(NULL, rlength);
+	if (!res) {
+		tmx_errno = E_ALLOC;
+		return NULL;
+	}
+
+	ret = ZSTD_decompress(res, rlength, source, slength);
+
+	if (ZSTD_isError(ret)) {
+		tmx_err(E_ZSDATA, "zstd_decompress: %s\n", ZSTD_getErrorName(ret));
+		goto cleanup;
+	}
+	if (ret < rlength) {
+		tmx_err(E_ZSDATA, "layer contains not enough tiles");
+		goto cleanup;
+	}
+
+	return res;
+cleanup:
+	tmx_free_func(res);
+	return NULL;
+}
+
+#else
+
+char* zstd_decompress(const char *source, unsigned int slength, unsigned int rlength) {
+	tmx_err(E_FONCT, "This library was not built with zstd support");
+	return NULL;
+}
+
+#endif /* WANT_ZSTD */
+
 /*
 	Layer data decoders
 */
@@ -237,14 +282,19 @@ int data_decode(const char *source, enum enccmp_t type, size_t gids_count, uint3
 			source++;
 		}
 	}
-	else if (type==B64Z) {
+	else if (type==B64 || type==B64Z || type==B64ZSTD) {
 		if (!(b64dec = b64_decode(source, &b64_len))) return 0;
-		*gids = (uint32_t*)zlib_decompress(b64dec, b64_len, (unsigned int)(gids_count*sizeof(int32_t)));
-		tmx_free_func(b64dec);
-		if (!(*gids)) return 0;
-	}
-	else if (type==B64) {
-		*gids = (uint32_t*)b64_decode(source, &b64_len);
+		if (type==B64ZSTD) {
+			*gids = (uint32_t*)zstd_decompress(b64dec, b64_len, (unsigned int)(gids_count*sizeof(int32_t)));
+			tmx_free_func(b64dec);
+		}
+		else if (type==B64Z) {
+			*gids = (uint32_t*)zlib_decompress(b64dec, b64_len, (unsigned int)(gids_count*sizeof(int32_t)));
+			tmx_free_func(b64dec);
+		}
+		else {
+			*gids = (uint32_t*)b64dec;
+		}
 		if (!(*gids)) return 0;
 	}
 

src/tmx_utils.h

@@ -87,7 +87,7 @@ void property_deallocator(void *val, const char *key);
 */
 #define MAX(a,b) (a<b) ? b: a;
 
-enum enccmp_t {CSV, B64Z, B64};
+enum enccmp_t { CSV, B64Z, B64, B64ZSTD };
 int data_decode(const char *source, enum enccmp_t type, size_t gids_count, uint32_t **gids);
 
 void map_post_parsing(tmx_map **map);

src/tmx_xml.c

@@ -375,6 +375,7 @@ static int parse_object(xmlTextReaderPtr reader, tmx_object *obj, int is_on_map,
 
 static int parse_data(xmlTextReaderPtr reader, uint32_t **gidsadr, size_t gidscount) {
 	char *value, *inner_xml;
+	enum enccmp_t data_type;
 
 	if (!(value = (char*)xmlTextReaderGetAttribute(reader, (xmlChar*)"encoding"))) { /* encoding */
 		tmx_err(E_MISSEL, "xml parser: missing 'encoding' attribute in the 'data' element");
@@ -391,11 +392,16 @@ static int parse_data(xmlTextReaderPtr reader, uint32_t **gidsadr, size_t gidsco
 		tmx_free_func(value);
 		value = (char*)xmlTextReaderGetAttribute(reader, (xmlChar*)"compression"); /* compression */
 
-		if (value && strcmp(value, "zlib") && strcmp(value, "gzip")) {
+		data_type = B64;
+		if (value && !strcmp(value, "zstd")) {
+			data_type = B64ZSTD;
+		} else if (value && !(strcmp(value, "zlib") && strcmp(value, "gzip"))) {
+			data_type = B64Z;
+		} else {
 			tmx_err(E_ENCCMP, "xml parser: unsupported data compression: '%s'", value); /* unsupported compression */
 			goto cleanup;
 		}
-		if (!data_decode(str_trim(inner_xml), value ? B64Z : B64, gidscount, gidsadr)) goto cleanup;
+		if (!data_decode(str_trim(inner_xml), data_type, gidscount, gidsadr)) goto cleanup;
 
 	} else if (!strcmp(value, "xml")) {
 		tmx_err(E_ENCCMP, "xml parser: unimplemented data encoding: XML");

tmxConfig.cmake.in

@@ -1,7 +1,12 @@
 include(CMakeFindDependencyMacro)
 find_dependency(LibXml2)
+
 if(@WANT_ZLIB@ AND NOT @EMSCRIPTEN@)
   find_dependency(ZLIB)
 endif()
 
+if(@WANT_ZSTD@)
+  find_dependency(ZSTD)
+endif()
+
 include("${CMAKE_CURRENT_LIST_DIR}/tmxExports.cmake")